JPH09243069A - Flame detector for burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flame detector for a burner which obtains stable electromotive force by reducing the influence of the fluctuation or variable size of a flame by using a thermocouple formed of two type of plate-like elements. SOLUTION: This flame detector for a burner comprises a thermocouple 28 for detecting a flame from a burner port and having two types of plate-like elements 28a, 28b in such a manner that a heat sensor 28c having the connected elements 28a, 28b is opposed to the burner port and disposed along the outer periphery of the position to be formed with the flame of the port and the sensor 28c is operated as a flame holder for the flame of the port 15b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame detection device for detecting the combustion state of a gas burner or the like, and more particularly to two types of plate-shaped thermocouples for detecting a flame from a flame outlet. The present invention relates to a flame detection device for a burner, which is composed of a body and has a heat-sensing portion in which these two types of plate-like bodies are joined and faces the flame outlet.

[0002]

2. Description of the Related Art Heretofore, taking a gas stove burner as an example, a sheath type thermocouple having a sharp heat-sensitive portion at its tip has been widely used as a thermocouple for flame detection. However, in such a sheath-type thermocouple, since the heat-sensitive part is sharp, the temperature rise is captured at a point, which is easily affected by the fluctuation of the flame due to the wind, and a stable electromotive force can be obtained. However, the thermocouple itself is expensive, so that the flame detecting device is expensive.

In order to solve such a conventional drawback, as disclosed in Japanese Patent Laid-Open No. 5-223220, a thermocouple is composed of two kinds of plate-like bodies, and the width of these two kinds of plate-like bodies is set. A structure has been proposed in which the directions are joined to each other to form a heat-sensitive portion, and the heat-sensitive portion faces the burner burner. In the thermocouple disclosed in this publication, since the heat-sensitive portion becomes wider in the direction orthogonal to the length direction of the flame formed at the flame mouth,
Less susceptible to flame fluctuations, a considerably more stable electromotive force is obtained compared to the above-mentioned sheath type thermocouple, and
The structure is simple and inexpensive.

[0004]

However, in the stove burner disclosed in the above publication, the two types of plate-like bodies are joined to each other only in the lateral width direction to form the heat-sensitive part, so that the heat-sensitive part of the thermocouple has a flame. Although it is wide in the direction perpendicular to the length direction of the flame, it becomes relatively short in the direction along the flame length direction, and the influence of the size of the flame is great, and there is room for improvement in this respect.

The present invention focuses on such a conventional problem, and an object thereof is to construct a thermocouple with a simple structure composed of two kinds of plate-like bodies, and to have an influence due to flame fluctuation. It is, of course, to provide a burner flame detection device that can obtain a stable electromotive force at all times with little influence of the size of the flame.

[0006]

In order to achieve this object, according to the invention as defined in claim 1, the thermocouple is composed of two kinds of plate-like bodies, and the heat-sensitive part thereof forms a flame at the flame mouth. It is arranged along the outer periphery of the planned location, and since this heat-sensitive part is configured to act as a flame holding plate against the flame at the flame mouth, the heat-sensitive part of the thermocouple is arranged in the length direction of the flame. Not only in the orthogonal direction, but also in the flame length direction,
Moreover, since it acts as a flame holding plate against the flame,
The flame is always in contact with the heat-sensitive part, and there is little influence due to the fluctuation of the flame or the influence of the size of the flame. Therefore, it is possible to always obtain a stable electromotive force with a simple structure consisting of two types of plate-like thermocouples. it can.

According to the second aspect of the present invention, the burner is a stove burner, the eaves portion is projected from the burner cap constituting the stove burner, and the eaves portion of the annular flame port is provided. The flame port located below is displaced to the center side of the burner body with respect to the other flame ports, and the secondary combustion chamber is formed by the flame port and the eaves portion that are displaced to the center side of the burner body,
Since the heat-sensitive part of the thermocouple is located below the sub-combustion chamber, it is possible to avoid direct contact of boiling water, etc. on the heat-sensitive part by the eaves forming the sub-combustion chamber as much as possible. It is possible to prevent the deterioration and deterioration, and also to prevent the thermocouple from being damaged due to the contact of another object, and to extend the service life of the thermocouple and enable the use for a relatively long period of time.

According to the third aspect of the invention, since the burner body is formed of sheet metal, the manufacturing cost can be reduced as compared with the case of casting and the burner body is formed. A portion of the sheet metal located below the eaves portion is bulged upward, and the bulged portion constitutes one of two types of plate-shaped bodies of the thermocouple, and the other plate-shaped body is bulged as described above. Since it is joined to the lower surface of the part, the burner body can also be used as it is for one plate-like body of the thermocouple to simplify the structure. By forming a pair, the position of the thermocouple with respect to the burner flame port can be easily determined, and a more stable electromotive force can be obtained. In addition, since the bulging portion is configured to cover the upper side and the peripheral portion of the other plate-shaped body forming the thermocouple, the two types of plate-shaped bodies, which are the heat-sensitive parts of the thermocouple, are joined together. There is no possibility that the part will be exposed to boiling water, and the service life of the thermocouple can be further extended and stable electromotive force can be obtained.

According to the fourth aspect of the present invention, in the bulging portion of the burner body that constitutes the thermocouple and the other plate-like body that is joined to the lower surface of the bulging portion, the bulging portion is corrosion resistant. Since the other plate-shaped body is made of a high material and has a low corrosion resistance, the plate having a low corrosion resistance is covered with the bulging portion having a high corrosion resistance to cover the upper surface and the peripheral portion and is completely protected from the flame. Therefore, the service life of the thermocouple can be further extended.

According to the fifth aspect of the present invention, the burner body is formed of two sheet metals, an upper plate and a lower plate, and the peripheral portions of the upper plate and the lower plate are overlapped with each other. Since the upper plate and the lower plate, which are superposed on each other, are bulged upward to form the bulging portion, for example, one of the plates forming the burner pipe line of the burner body in which the combustion mixture flows. Compared to the case of bulging the part, the flow of the combustion mixture is maintained as desired without disturbing the flow of the combustion mixture, and despite bulging a part of the burner body. A stable flame due to good combustion can be obtained.

According to the sixth aspect of the present invention, the burner body is formed of two sheet metals, an upper plate and a lower plate, and the peripheral portions of the upper plate and the lower plate are overlapped with each other. ,
Since a part of the lower plate is cut out and the upper plate of a portion corresponding to the cutout portion is bulged upward to form the bulged portion, one plate-shaped body of the thermocouple can be formed. Only the upper plate is configured, and the heat capacity of the thermosensitive part of the thermocouple can be reduced compared to when both the upper plate and the lower plate are bulged. Can be improved.

According to the seventh aspect of the invention, since the peripheral portion of the cutout portion of the lower plate and the upper plate are connected to each other by caulking, the structure is simpler than the connection by welding. It is possible to prevent leakage of the air-fuel mixture for combustion from between the peripheral portion of the cutout portion of the lower plate and the upper plate.

According to the eighth aspect of the present invention, since the peripheral portion of the cutout portion of the lower plate and the upper plate are deformed and connected to each other, the peripheral portion of the cutout portion of the lower plate and the upper portion are connected. It is possible to more reliably prevent the combustion mixture from leaking from between the plates.

According to the ninth aspect of the present invention, of the two types of plate-like bodies forming the thermocouple, the plate-like body having high corrosion resistance forms the upward bulging portion, and the bulging portion Since a plate-like body having low corrosion resistance is joined to the lower surface and the bulging portion is configured to cover the upper part and the peripheral portion of the plate-like body having low corrosion resistance, the plate-like body having low corrosion resistance is The high bulging portion of the thermocouple completely protects it from broth and flames, extending the service life of the thermocouple and joining the plate-shaped body that forms the bulging portion to the burner body. Therefore, the joint to the burner body is also strong, and since it is possible to configure only the bulging portion with a necessary material, for example, stainless steel, the burner body is made of a relatively inexpensive material. Can and burner costume It can be achieved down.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a flame detection device for a burner according to the present invention will be described with reference to the drawings. The drawings show a burner for a gas stove. As shown in FIGS. 1 to 3, the burner is a mixing pipe 1 for mixing and supplying a fuel gas and primary air for combustion, and is connected to the mixing pipe 1. The burner body 2 has a substantially annular shape and is provided with a burner cap 3 fitted and mounted on the burner body 2. The mixing tube 1 and the burner body 2 are made of stainless steel and bent into a predetermined shape. The upper plate 4a and the lower plate 4b are made of stainless steel.
The upper plate 4a and the lower plate 4b are integrally formed by overlapping the peripheral portions and necessary portions of each other and connecting them by caulking or the like.

On the base end side of the mixing tube 1, the mixing tube 1
A gas nozzle 6 for supplying a fuel gas is arranged in the mixing pipe 5 formed by the above, and an intake port 7 for sucking the primary air for combustion is provided on the outer peripheral portion of the gas nozzle 6, and A damper 8 for adjusting the amount of primary air sucked from the suction port 7 is also provided. The mixing conduit 5 is connected to an annular burner conduit 9 formed by the burner main body 2, and the upper surface of the burner main body 2 has:
A plurality of communication holes 11 for communicating the annular space 10 formed by the burner body 2 and the burner cap 3 with the burner pipe 9 are bored, and the burner body 2
A circular central opening 12 for taking in secondary air is formed in the central portion of the so as to penetrate in the vertical direction.

The burner cap 3 is formed separately from the mixing tube 1 and the burner body 2, and a cylindrical portion 13 integrally connected to the lower portion of the burner cap 3 is fitted in the central opening 12 of the burner body 2. Is configured so that it can be placed and held on the burner body 2, and in this placed and held state, the annular space 10 is formed between the burner body 2 and the burner cap 3. As shown in FIG. 4, on the lower surface of the outer peripheral portion of the burner cap 3, a plurality of fuel gas ejection recesses 14 and two types of fuel gas that are slightly deviated to the center side from the fuel gas ejection recesses 14 are formed. Jet recesses 14a, 14
b formed over the entire circumference, and in a state where the burner cap 3 is placed on the burner body 2, a plurality of main flames annularly arranged by the gas ejection recesses 14, 14a, 14b and the burner body 2. Ports 15, 15a, 15b are formed to communicate with the annular space 10, and the internal space of the cylindrical portion 13 is concentric with the central opening 12 of the burner body 2.

A cylindrical heat shield wall 16 is integrally formed on the upper portion of the burner cap 3 concentrically with the lower cylindrical portion 13, and secondary air is supplied below the heat shield wall 16. An outward opening 17 for forming the heat shield wall 16 and the cylindrical portion 13 are integrally connected by a plurality of connecting portions 18. At the lower end of the heat shield wall 16, the air supplied from the central opening 12 of the burner body 2 is divided into the inside of the cylindrical heat shield wall 16 and the opening 17 side, and the opening 17
A diversion wall 19 for integrally guiding the secondary air from the outside toward the radial outside is continuously provided. Further, in this burner cap 3, circumferentially long gas ejection holes 20 penetrating in the up-down direction are bored at three locations in the inner part of the annular groove for forming the annular space 10, and each gas is provided. A cover portion 21 is integrally formed with the burner cap 3 above the ejection hole 20 to guide the gas ejected upward from the gas ejection hole 20 obliquely upward in the radial direction. An auxiliary flame port 22 different from the main flame ports 15, 15a, 15b is formed.

Therefore, when the burner cap 3 is placed on the burner body 2, the fuel gas from the mixing conduit 5 is supplied into the annular space 10 via the burner conduit 9 and each communication hole 11. , This annular space 10 to the main flame port 1
It is ejected toward the outside in the radial direction via 5, 15a and 15b and forms an annular main flame by combustion. at the same time,
The fuel gas in the annular space 10 is ejected obliquely outward in the radial direction via the auxiliary flame port 22 and is burned by auxiliary flames that are longer in the circumferential direction at three locations radially inward than the annular main flame. To form. Then, secondary air for combustion is supplied to the main flame and the auxiliary flame from the opening 17.

An expandable rod-shaped holding member 24 for holding an overheat state detecting sensor 23 such as a thermistor is located in the central opening 12 of the burner body 2 so as to detect the bottom temperature of the cooking pot or the like. Is configured.
That is, the holding member 24 is attached to a stove frame or the like (not shown) and is configured to be expandable / contractible by a spring or the like, and an overheat state detection sensor 23 is attached to the upper end of the holding member 24 to attach the burner cap 3 to the burner. The overheat state detection sensor 23 is configured to project slightly above the upper end surface of the burner cap 3 when placed on the main body 2.

Therefore, when a cooking pot or the like is placed on the stove, the bottom surface of the cooking pot comes into contact with the overheated state detection sensor 23 to compress the holding member 24, and the bottom surface of the cooking pot and the overheated state detection sensor 23 are combined. While maintaining the contact state, the heat shield wall 16 covers the outer peripheral portion of the overheat state detection sensor 23 to shut off heat from the flame, and reliably detects the temperature of the bottom surface of the cooking pot. When the temperature detected by the overheat state detection sensor 23 becomes equal to or higher than a preset temperature, an alarm device (not shown) is activated, or a solenoid valve provided in the fuel supply path is closed to operate the fuel gas. By stopping the supply,
Prevents burning and overheating of cooked foods.

On the lower side of the burner main body 2 opposite to the mixing tube 1, a sheet metal terminal 25 bent and formed into a predetermined shape is attached, and the terminal 25 has main flame ports 15, 15a, A spark plug 26 for spark discharge is attached to ignite 15b. The spark plug 26 has an insertion hole 27 formed in the outer peripheral portion of the burner body 2.
Is protruded upwards through the main end of the main flame outlet 1
It is arranged so as to face 5a. This spark plug 26
On the lateral side of the insertion hole 27 for use, a part of the upper plate 4a made of stainless steel forming the burner body 2 is bulged so that its upper surface is directed obliquely upward in a state of having an appropriate lateral width and length. Then, as shown in FIG. 5, a plate-shaped body 28b made of constantan is joined to the lower surface of the bulging portion 28a by spot welding or the like over an appropriate length, and the bulging portion 28a of the stainless steel upper plate 4a and the constantan 28a. The plate-shaped body 28b made of a thermocouple 28 for detecting the burner flame.

In the lower plate 4b corresponding to the bulging portion 28a of the upper plate 4a, a portion corresponding to the bulging portion 28a is partially cut away, and as shown in FIG.
The peripheral portion of the cutout portion 29 of b and the upper plate 4a are caulked and connected to each other. As is clear from FIG. 5 and FIG. 6, the bulging portion 28a made of stainless steel, which has higher corrosion resistance than constantan, is formed not only on the upper surface of the plate-like body 28b made of constantan having low corrosion resistance, but also on the peripheral portion thereof. It is constructed so that it covers completely and completely.

At the portion of the burner cap 3 where the spark plug 26 and the thermocouple 28 are located, eaves portions 30 and 31 for covering the upper portion of the spark plug 26 and the thermocouple 28 are integrally connected to each other. The gas ejection recesses 14a and 14b corresponding to the portions 30 and 31 are arranged at positions slightly closer to the center side than the other gas ejection recesses 14. That is,
The main flame port 15a exposed by the spark plug 26 is the other main flame port 15a.
The main flame port 15a and the eaves portion 30 which are deviated toward the center side are formed to form an auxiliary combustion chamber 32 for ignition, and the ignition plug 26 is positioned in the auxiliary combustion chamber 32 for ignition. There is. Similarly, the main flame port 15 facing the joint between the bulging portion 28a, which is the heat-sensitive portion 28c of the thermocouple 28, and the plate-like body 28b.
b is also deviated to the center side from the other main flame port 15, and the deviated main flame port 15b and the eaves portion 31 form a flame detection auxiliary combustion chamber 33, and the flame detection auxiliary combustion chamber 33 is formed. The thermosensitive portion 28c of the thermocouple 28 is arranged in the chamber 33,
Further, the eaves portion 30 that covers the ignition plug 26 from above is integrally provided with the electrode projection 34 for discharge.

Since the heat-sensitive portion 28c of the thermocouple 28 has an appropriate lateral width and is arranged obliquely so as to be located further away from the center of the burner main body 2, the flame detection auxiliary combustion is performed. In the chamber 33, it is located below the outer periphery of the flame formation scheduled portion of the main flame port 15b, and acts as a flame holding plate for the main flame. This thermocouple 2
When the main flame 8 is heated by the main flame during burner combustion, a predetermined thermoelectromotive force is generated, and based on the thermoelectromotive force, an unillustrated valve-closed solenoid valve provided in the fuel supply path is opened. For example, when the flame of the burner is extinguished due to, for example, the overflow of broth, the electromagnetic valve is stopped and the solenoid valve is closed. The anode side lead wire is connected to the burner body 2 side, and the cathode side lead wire is connected to the plate-shaped body 28b made of constantan.

[Another Embodiment] In the above embodiment,
In FIG. 6, the peripheral portion of the cutout portion 29 of the lower plate 4b and the upper plate 4
Although the structure in which a and caulk are connected to each other is shown,
As shown in FIG. 7, the peripheral portion of the cutout portion 29 of the lower plate 4b and the upper plate 4a are deformed and connected to each other, or
Various connecting structures such as deforming and crimping each other can be adopted. Further, as shown in FIG. 8, the upper plate 4a is not provided with the notch 29 as in the previous embodiments.
The lower plate 4b and the lower plate 4b are both bulged upward to form a bulged portion 28a, and a plate-like body 28b made of constantan is joined to the lower surface of the lower plate 4b forming the bulged portion 28a to join the thermocouple 2
8 can also be configured.

FIG. 9 shows still another embodiment.
The stainless bulging portion 28a that constitutes the thermocouple 28 is formed separately from the upper plate 4a and the lower plate 4b of the burner body 2, and a plate made of constantan is formed on the lower surface of the stainless bulging portion 28a by spot welding or the like. The body 28b is joined to form the thermocouple 28, and the bulging portion 28a made of stainless steel is configured to completely cover the upper surface and the peripheral portion of the plate 28b made of constantan, and By fixing the bulging portion 28a to the upper plate 4a and the lower plate 4b,
The thermosensitive portion 28c of the thermocouple 28 may be arranged obliquely with a proper width to act as a flame holding plate. In this case, the upper plate 4a and the lower plate 4
If b is not necessarily made of stainless steel, and if it is made of a material other than stainless steel, the anode side lead wire is directly connected to the bulging portion 28a made of stainless steel.

In the above-described embodiments, the swelling portion 28a made of stainless steel is used to cover the upper surface and the peripheral portion of the plate member 28b made of constantan in a completely wrapped state. Alternatively, it may be configured so as to cover only the upper surface of the plate 28b made of constantan. That is, in the bulging portion 28a whose upper surface is directed obliquely upward, the main flame port 15
It has a total of three surfaces, one surface located on the tip side of the main flame formed by b and two triangular surfaces located on the lateral side, but these three surfaces are not always necessary. As long as it covers at least the upper surface of the plate made of constantan 28a and acts as a flame holding plate, even if the tip side is open, one or both of the lateral sides is open. It can be implemented even with an open shape.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the attached drawings.

[Brief description of drawings]

FIG. 1 is a plan view of a burner for a gas stove.

FIG. 2 is a sectional view taken along the line P-O-R in FIG.

FIG. 3 is an exploded perspective view of a gas stove burner.

FIG. 4 is a bottom view of the burner cap.

FIG. 5 is a sectional view of a main portion of a burner showing a thermocouple.

FIG. 6 is a front view of the thermocouple.

FIG. 7 is a front view of a thermocouple showing another embodiment.

FIG. 8 is a front view of a thermocouple showing another embodiment.

FIG. 9 is a perspective view of an essential part showing another embodiment.

[Explanation of symbols]

 2 burner main body 3 burner cap 4a upper plate 4b lower plate 15, 15b flame mouth 28 thermocouple 28a bulging portion made of a plate having high corrosion resistance 28b plate having low corrosion resistance 28c heat sensitive part 29 notch part 31 eaves part 33 Secondary combustion chamber

Claims (9)

[Claims] 1. A thermocouple (28) for detecting a flame from a flame port (15) is composed of two kinds of plate-like bodies (28a) and (28b), and these two kinds of plate-like bodies (28a) are provided. , (28
A flame detecting device for a burner, wherein a heat-sensitive part (28c) joined to b) is made to face the flame opening (15), and the heat-sensitive part (28c) is provided in a flame formation portion of the flame opening (15). This heat-sensitive part (28c) is arranged along the outer circumference.
Is a burner flame detection device configured to act as a flame holding plate against the flame of the flame port (15). 2. A stove burner in which the burner has an annular flame port (15) at a peripheral portion formed by a burner body (2) and a burner cap (3) located above the burner body (2). Then, the eaves part (31) is projected from the burner cap (3), and the annular flame port (15) is provided.
Of the flame mouth (15) located below the eaves (31) of the
b) is displaced more toward the center side of the burner body (2) than the other flame openings (15), and is displaced toward the center side of the burner body (2) and the eaves portion (31). The flame detection device for a burner according to claim 1, wherein a sub-combustion chamber (33) is formed by and the heat-sensitive portion (28c) of the thermocouple (28) is located below the sub-combustion chamber (33). . 3. The burner body (2) is formed of sheet metal,
A portion of the sheet metal forming the burner body (2) located below the eaves portion (31) is bulged upward, and the bulging portion (28a) allows two types of the thermocouple (28). One of the plate-like bodies is formed, and the other plate-like body (28
b) is joined to the lower surface of the bulging portion (28a), and the bulging portion (28a) allows the other plate-like body (2) to be joined.
The burner flame detection device according to claim 2, wherein the flame detection device is configured so as to cover the upper portion and the peripheral portion of 8b). 4. A bulging portion (28a) of the burner body (2) constituting the thermocouple (28) and the bulging portion (28).
In another plate-like body (28b) joined to the lower surface of a), the bulging portion (28a) is made of a material having high corrosion resistance, and the other plate-like body (28b) is made of a material having low corrosion resistance. The flame detection device for a burner according to claim 3. 5. The burner body (2) is composed of two metal plates, an upper plate (4a) and a lower plate (4b), and these upper plates (4).
a) and the lower plate (4b) are overlapped with each other, and the upper plate (4a) and the lower plate (4b) thus overlapped are bulged upward to form the bulged portion (28a). The burner flame detection device according to claim 3 or 4, wherein the flame detection device is formed. 6. The burner body (2) is composed of two sheet metals, an upper plate (4a) and a lower plate (4b), and these upper plates (4).
a) and the lower plate (4b) are overlapped with each other, and a part of the lower plate (4b) is cut out,
Upper plate (4a) of a portion corresponding to the cutout (29)
The burner flame detection device according to claim 3 or 4, wherein the bulging portion (28a) is formed by bulging upward. 7. A notch (29) in the lower plate (4b).
The burner flame detection device according to claim 6, wherein a peripheral portion of the burner is connected to the upper plate (4a) by caulking each other. 8. A notch (29) in the lower plate (4b).
7. The burner flame detection device according to claim 6, wherein the peripheral portion of the and the upper plate (4a) are deformed and connected to each other. 9. Of the two types of plate-like bodies (28a), (28b) constituting the thermocouple (28), a plate-like body having high corrosion resistance forms an upward bulging portion (28a), On the lower surface of the bulging portion (28a), a plate-like body (2
8b) is joined, and the bulging portion (28a) is configured to cover the upper portion and the peripheral portion of the plate-like body (28b) having low corrosion resistance, and the bulging portion (28a) is formed. The burner flame detection device according to claim 2, wherein the plate-like body is joined to the burner body (2).